1. Field of Invention
The present invention relates to an electronic device. More particularly, the present invention relates to an electronic device with several charging modes.
2. Description of Related Art
With advances in technology, more and more electronic products are becoming available to the public. The development of electronic products, such as pen drives, MP3 players, digital cameras, etc., brings comforts and convenience to people. The above-mentioned electronic device is a device that is convenient to carry, mobile, and highly compatible with many different computers. People can transfer or backup data between the electronic device and a computer quickly and safely, no matter if the data is an image, a document, or audio and video signals. People can move the electronic device between different computers so that data can be accessed to and from different computers. Presently, the storage sizes of the electronic devices are increasing due to research and development in component fabrication.
The electronic devices in the prior art can generally be divided into two categories. The first category includes devices each of which has an external power supply. This kind of device is called a BUS-powered device, wherein the pen drive is an example of a BUS-powered device. The second category includes devices each of which has an internal power supply. This kind of device is called a self-powered device, wherein the multi-media player is an example of a self-powered device. The BUS-powered devices obtain power externally through the Universal Serial Bus (USB). The self-powered devices are further divided into three sub-categories as below.
In the first sub-category, a self-powered device includes a DC power module. The DC power module includes a DC power terminal to electrically connect to a transformer, wherein the transformer is capable of transforming an AC power, for example, 110V/60 Hz, into a corresponding DC power for the external electronic device.
In the second sub-category, the electronic device is internally equipped with a battery module, wherein the battery can include a primary battery or a rechargeable battery, to provide stable DC power to the external electronic device. For the battery module including a rechargeable battery, if the electronic device is electrically connected to a personal computer (PC) through a USB, the electronic device can obtain operating power from the computer through the USB. Meanwhile, the electronic device can store the power obtained in a rechargeable battery to recharge the rechargeable battery.
In the third sub-category, both the battery module and the DC power module are installed within the electronic device, such that the electronic device is capable of obtain operating power and charging power from a computer that the device is connected to, and is capable of obtaining DC power to operate and charge the transformer.
However, for the self-powered electronic device in the prior art, it is necessary to install a USB terminal and a DC power terminal on the housing at the same time to support the battery module and the DC power module simultaneously. Hence the cost of the components, design and fabrication of the electronic device is increased, and the housing is oversized. For the forgoing reasons, there is a need for electronic devices with a plurality of charging modes.